A Dynamic Bronchial Airway Gene Expression Signature of COPD and Lung Function Impairment.

Department of Medicine, Division of Computational Biomedicine, Boston University School of Medicine, Boston, Massachusetts, United States.
American Journal of Respiratory and Critical Care Medicine (Impact Factor: 13). 03/2013; 187(9). DOI: 10.1164/rccm.201208-1449OC
Source: PubMed


RATIONALE: Molecular phenotyping of COPD has been impeded in part by the difficulty in obtaining lung tissue samples from individuals with impaired lung function. OBJECTIVES: We sought to determine whether COPD-associated processes are reflected in gene-expression profiles of bronchial airway epithelial cells obtained via bronchoscopy. METHODS: Gene expression profiling of bronchial brushings obtained from 238 current and former smokers with and without COPD was performed using Affymetrix Human Gene 1.0 ST Arrays. MEASUREMENTS AND MAIN RESULTS: We identified 98 genes whose expression levels were associated with COPD status, FEV1% predicted, and FEV1/FVC. In silico analysis identified ATF4 as a potential transcriptional regulator of genes with COPD-associated airway expression, and ATF4 overexpression in airway epithelial cells in vitro recapitulates COPD-associated gene expression changes. Genes with COPD-associated expression in the bronchial airway epithelium had similarly altered expression profiles in prior studies performed on small-airway epithelium and lung parenchyma, suggesting that transcriptomic alterations in the bronchial airway epithelium reflect molecular events found at more distal sites of disease activity. Many of the airway COPD-associated gene expression changes revert toward baseline following therapy with the inhaled corticosteroid fluticasone in independent cohorts. CONCLUSIONS: Our findings demonstrate a molecular field of injury throughout the bronchial airway of active and former smokers with COPD that may be driven in part by ATF4 and is modifiable with therapy. Bronchial airway epithelium may therefore ultimately serve as a relatively accessible tissue in which to measure biomarkers of disease activity for guiding clinical management of COPD.

40 Reads

  • American Journal of Respiratory and Critical Care Medicine 05/2013; 187(9):900-2. DOI:10.1164/rccm.201302-0340ED · 13.00 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A core feature of chronic obstructive pulmonary disease (COPD) is the accelerated decline in forced expiratory volume in one second (FEV1). The recent Groningen and Leiden Universities study of Corticosteroids in Obstructive Lung Disease (GLUCOLD) study suggested that particular phenotypes of COPD benefit from fluticasoneĀ±salmeterol by reducing the rate of FEV1 decline, yet the underlying mechanisms are unknown. Whole-genome gene expression profiling using the Affymetrix Gene ST array (V.1.0) was performed on 221 bronchial biopsies available from 89 COPD patients at baseline and after 6 and 30 months of fluticasoneĀ±salmeterol and placebo treatment in GLUCOLD. Linear mixed effects modelling revealed that the expression of 138 genes decreased, whereas the expression of 140 genes significantly upregulated after both 6 and 30 months of treatment with fluticasoneĀ±salmeterol versus placebo. A more pronounced treatment-induced change in the expression of 50 and 55 of these 278 genes was associated with a lower rate of decline in FEV1 and Saint George Respiratory Questionnaire, respectively. Genes decreasing with treatment were involved in pathways related to cell cycle, oxidative phosphorylation, epithelial cell signalling, p53 signalling and T cell signalling. Genes increasing with treatment were involved in pathways related to focal adhesion, gap junction and extracellular matrix deposition. Finally, the fluticasone-induced gene expression changes were enriched among genes that change in the airway epithelium in smokers with versus without COPD in an independent data set. The present study suggests that gene expression in biological pathways of COPD is dynamic with treatment and reflects disease activity. This study opens the gate to targeted and molecular phenotype-driven therapy of COPD.
    Thorax 08/2013; 69(1). DOI:10.1136/thoraxjnl-2012-202878 · 8.29 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cigarette smoke contains numerous chemical compounds, including abundant reactive oxygen/nitrogen species and aldehydes, and many other carcinogens. Long-term cigarette smoking significantly increases the risk of various lung diseases, including chronic obstructive pulmonary disease and lung cancer, and contributes to premature death. Many in vitro and in vivo studies have elucidated mechanisms involved in cigarette smoke-induced inflammation, DNA damage, and autophagy and the subsequent cell fates, including cell death, cellular senescence, and transformation. In this review, we summarize the known pathways underlying these processes in airway epithelial cells to help reveal future challenges and describe possible directions of research that could lead to better management and treatment of these diseases.
    American Journal of Respiratory Cell and Molecular Biology 10/2013; 50(3). DOI:10.1165/rcmb.2013-0348TR · 3.99 Impact Factor
Show more

Similar Publications